300 Norma & 225 ELD-M Sweet Spot Velocity

[Bulldog Firearms]

Anyone with any experience have a feeling for the sweet spot velocity on a 225 ELD-M is going to be?

Had some issues with a current batch of loads done in the same way. Same lot of brass, same lot of bullets, same lot of powder, same lot of primers, when I loaded it, it shot just fine. Sub 1/2 moa grouping at 100 yards and 7 fps E/S over magnetospeed. Loaded up another batch about 3 months later and have sticky bolt lift and 30+ fps E/S. Broke down 3 cases out of each batch and over my A&D FX123 powder charge varied from 83.5 to 83.54. Furthermore it was colder outside too by 40 degrees.

26" 1-9 Twist Barrel on a DTA.

Norma Brass

83.5 H1000

CCI 250 Magnum Rifle Primer

Hornady 225 ELD-M

3.435 OAL

Velocity on first batch was 2980.

Velocity on second batch was 3020+.

That doesn't inspire confidence in my ability to reload.

Watched this video, https://www.youtube.com/watch?v=ACyfeeBHVOA and figured I'd give it a shot.

 

[Sendit6.5]

Is it a new barrel? If so, you may just be experiencing the velocity increase that many barrels experience as they break in. Are you checking BTOL rather than OAL? OAL is useless/irrelevant to me except to know whether a round will fit in my magazine. Base To Ogive Length IS important to know and verify! If you’re seating your bullets up close to the lands (rifling) and you’re not checking BTOL on each one, that can increase pressure/velocity - a few thousandths OFF the lands will give you less velocity than actually engaging them, which will increase velocity and pressure. If you’re not using BTOL, I would suggest getting a Stony Point comparator and using it along with the Hornady modified case tool and your chosen bullet.

There are all sorts of causes for velocity changes but that scale is a really good one so the obvious possibility of inaccurate powder charge is eliminated. The fact that the increase was in 40° cooler weather suggests that you probably have an even bigger shift than 40fps.

Possibly severe copper fouling in the barrel? Just throwing some possibilities out there.

I’ve been using Saterlee’s method here lately to speed up my OCW method and it seems to work well. I’m not ready to throw out OCW but by using Saterlee’s method I’ve been able to narrow down a charge weight range to test using an abbreviated OCW test. It’s saved me some components and time.


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